Circle Using Circles

#include<graphics.h>
#include<conio.h>
#include<math.h>
#include<dos.h>
void main()
{
 int gd=DETECT,gm,midx,midy,r=200,i,r1=10;
 int x1=(r/2)*sqrt(3),y1=r/2,x2=r/2,y2=(r/2)*sqrt(3);
 int a;
 float w1=sin(a),w2=cos(a);
 initgraph(&gd,&gm,"c:\\turboc3\\bgi");
 midx=getmaxx()/2;midy=getmaxy()/2;
 for(a=0;a<=360;a=a+5)
 {
  circle(midx+(r*cos(a)),midy-(r*sin(a)),r1);
 }
 getch();
 closegraph();
}